Android support

[claudeha]

The old Makefile template from SVN had support for Android (which may have bitrotted; I haven't tried it myself..). Could be nice if this build system supported it also.

Example in the wild: https://github.com/agraef/pd-lua/blob/master/Makefile#L158-L191

[katjav]

Would be nice indeed. I'm totally unfamiliar with this but here's some remarks for anyone who wants to add Android support.

Makefile.pdlibbuilder's internal variables are all written in lower case (in contrast with the old Makefile template). Upper case variables are intended for the user as make command argument or environment variable. In the case of cross compilation the user will define PLATFORM to hold the target triplet. Makefile.pdlibbuilder stores the isolated components thereof as a list in variable target.triplet. From there, target system Android could be detected like so:

ifneq ($(filter android%, $(target.triplet)),)
  system = Android
endif

and the Android section would start like:

ifeq ($(system), Android)

The Android section must be evaluated after the general Linux section so it can inherit some variable definitions and overwrite others.